Glass is getting too dark...

[kintuX]

We were talking of the first image, of dispersion and Cauchy's equation: how can be Cycles used as reference if it doesn't support dispersion at all

Can simulate dispersion in Cycles with shader nodes, separating RGB chanels using different IORs and adding, summing it back.

That is not even vaguely dispersion.

Am aware... still, the issue here is with the loss of energy when dispersion is used - makes it unusable with clamping.
IMHO, in archviz, product & jewelry viz this is one of those details that either make or break the deal.

Cycles FAKE dispersion:

Maxwell Render 100% dispersion:

Quite much inconsistencies in values among different engines so i'm gonna continue exploring, comparing, searching for optimal solution and post notes/thoughts here. I guess learning & correcting mistakes (fixing bugs) never ends. & Of course, am gonna use LuxCore with proper/better values, yet still do tests with others engines: Indigo, Ocean, Iray, VRay, Octane, RedShift, appleseed, Arnold, Corona, PRMan...
Tho strangest thing, except Cycles, no other engine i know off (even those that claim to simulate physically correct - ground truth) uses multi-scattered GGX model, which in most cases helps a lot in realistic shading. I remember how fast had been implemented in Cycles. But lots of other stuff is missing, so...

... the traveling continues.


Thanks again and keep the genius alive.

[lacilaci]

IMHO, in archviz, product & jewelry viz this is one of those details that either make or break the deal.

Not at all. From all those mentioned only jewelry really needs dispersion in commercial work and even corona or vray can do that.
Things need to look good, look convincing and render fast in all those fields mentioned. And that is why corona and vray are dominating them.

[FarbigeWelt]

Also the issue with clear glass might just be the values that you are using. The tool tip for dispersion says:
"Realistic values range from 0.00354 to 0.01342"

Yes, you go out of visible spectrum out of an healthy range.

Hi Dade, on my search for appropriate dispersion values, Cauchy c for diamond or other minerals, I've always got comparision to Sellmeier. Sellmeier would be even more realistic than Cauchy. Will there be an implementation of Sellmeier someday or does it demand too many calculation to be usefull?

[FarbigeWelt]

Clear glass does not have any colors, it cannot be dark. The appearing color depends on refraction/dispersion/reflexions, the environment and its shape. We mostly think we know how glass should look like, but we acutally cannot imagine realistic pictures of glass. At least I can't.

EDIT: image added.

Glasses CPU BiDir 800 Samples 7 h 2400x2000

Native rough glass with dispersion would be nice. Is there a special reason why this is not supported? It is not clear what happens when rough glass is mixed with disperesed glass because it does not look like if one mixes to images. I may have a closer look at this topic before I post a picture.

Glass mixed with glossy looks what I expceted. Another idea is to take a few good picture from different empty wine glasses, make some models and compare renderings with the pictures. Meanwhile my expectations how glass should look like are under suspicion.

To me it simply feels as too dark

Where is your point of view, to claim "Glass is getting dark?"
What color has the sea, or a lake, or even a pool? What time is it?